Solar energy is widely accepted as being an excellent source of renewable energy. Photovoltaic (PV) cells which can convert sunlight into electricity have been studied for the past ˜70 years. The adoption and wide spread use of PV cells has been slow because they have exhibited poor conversion efficiency and have been expensive to manufacture. Therefore, the economics ($/Watt) of using PV cells to generate electricity have not been competitive with traditional sources such as coal, oil, natural gas, etc. The $/Watt metric represents the total system cost to generate a Watt of energy. Lower PV solar cell efficiencies and higher PV solar cell system costs increase this metric and lowers the competitiveness of the PV solar cell system relative to traditional energy generation systems.
Recent advances in the design and manufacture have improved the efficiency of the PV solar cells and lowered the manufacturing cost such that PV based solar energy systems have improved economics. It is a goal that PV based solar energy systems will be able to generate electricity at costs that are competitive with traditional electricity generation methods in the near future. For this goal to be realized, advances must be made to continue to improve the conversion efficiency of the PV solar cells and to lower the manufacturing costs.
In another step in the manufacture of PV solar cells or TF modules, substrates are often processed in equipment used to expose the substrates to various gases. The substrates may be heated and the gases may be used to dope the substrates to change their electrical or chemical properties, deposit materials on the substrates, remove materials from the substrates, or change the surface properties of the substrates among others. In the case wherein the equipment contains a large enclosure used to treat a large batch of substrates simultaneously, it is important that the substrates are processed uniformly.
Current equipment used for treating substrates with a gas during the manufacture of PV based solar cells or TF modules suffer from a number of problems. Examples of these problems may be high equipment cost, low throughput, large footprint, poor performance, non-uniform supply of the gas, non-uniform exhaust of the reaction by-products, and others. These problems may act individually or in combination to lower the efficiency of the PV solar cells or TF modules or increase the cost of manufacturing the PV solar cells or modules. This will increase the $/Watt economic metric used to evaluate energy system performance and slow the adoption of PV solar energy systems. Therefore, there is a need for gas delivery and exhaust handling systems to be used in equipment used to manufacture PV solar cells or modules that address these problems.